Reactivation of hepatitis B (reverse seroconversion) after melphalan/dexamethasone therapy for primary amyloidosis: a case report

INTRODUCTION Hepatitis B virus (HBV) reactivation (so-called reverse seroconversion) is a rare but known complication of hematopoietic stem cell transplantation, immunosuppressive therapy, or high-dose chemotherapy plus rituximab. This event is linked to a treatment-related fall in titers of antibodies to hepatitis B surface antigen (HBsAb) below the protective threshold level. CASE PRESENTATION A 77-year-old Korean man diagnosed with primary amyloidosis was started on melphalan/dexamethasone combination therapy. During treatment, laboratory indices of hepatic function suddenly deteriorated, and he developed acute hepatitis through reverse HBV seroconversion, becoming positive for hepatitis B surface antigen (HBsAg) and negative for HBsAb. HBV DNA was also detectable in serum to a profound extent. Normal liver function was gradually restored during the course of antiviral therapy (entecavir). CONCLUSIONS HBV reactivation may lead to fatal liver disease in a significant percentage of patients. As a result, physicians often screen for HBsAg and HBsAb prior to initiating chemotherapy, advising antiviral treatment in patients seropositive for HBsAg, even in the absence of hepatitis B e antigen. Here, a case of HBV reactivation is described, involving a patient given relatively low-dose chemotherapy (melphalan/dexamethasone) for primary amyloidosis.